The present invention relates to a semiconductor device and a method of manufacturing thereof and, more particularly, to the incorporation of both low and high voltage BiCMOS elements in one chip.
Recently, according to the high-speed and miniaturization trend of electronic products, the developments of semiconductor devices with multi-function which compose semiconductor elements with different functions and different driving voltages in one chip have been competed.
Generally, the semiconductor device which has bipolar transistor and CMOS transistor within one chip is called BiCMOS. The conventional BiCMOS of VLSI(Very Large Scale Integrated Circuit) level has been suitable for high integration and high speed logic since they have been designed for high performance memory and logic driven by a low voltage as introduced in ISSCC Digest of Technical Papers, February, 1986, p. 212 and CICC Tech. Dig., May, 1986, p. 68.
Also, BiCMOS which is driven by a high voltage to increase output power and noise margin has been developed. However, there is a problem in achieving the high speed operation and miniaturization of electronic products, since such electronic products which use both the low and high voltage BiCMOS have to be loaded with many semiconductor devices and so there are difficulties in achieving the high speed operation and miniaturization of such electronic products.